Probes for INS

In recent years, chimeric antigen receptor-modified T cell (CAR T cell) therapy has proven to be a promising approach against cancer. Nonetheless, this approach still faces multiple challenges in eliminating solid tumors, one of which being the immunosuppressive tumor microenvironment (TME). Here, we demonstrated that knocking out the endogenous TGF-? receptor II (TGFBR2) in CAR T cells with CRISPR/Cas9 technology could reduce the induced Treg conversion and prevent the exhaustion of CAR T ce lls. Meanwhile, TGFBR2-edited CAR T cells had better in vivo tumor elimination efficacy, both in cell line-derived xenograft and patient-derived xenograft solid tumor models, whether administered locally or systemically. In addition, the TGFBR2-edited CAR T cells could eliminate contralaterally reinoculated xenografts in mice effectively, with an increased proportion of memory subsets within circulating CAR T cells of central memory and effector memory subsets. In conclusion, we greatly improved the in vitro and in vivo function of CAR T cells in TGF-?-rich tumor environments by knocking out endogenous TGFBR2 and propose a potentially new method to improve the efficacy of CAR T cell therapy for treating solid tumors

Bacterial lipoproteins are an often-underappreciated class of microbe-associated molecular patterns with potent immunomodulatory activity. We previously reported that vaccination of BALB/c mice with Mycoplasma pneumoniae (Mp) lipid-associated membrane proteins (LAMPs) resulted in lipoprotein-dependent vaccine enhanced disease after challenge with virulent Mp, though the immune responses underpinning this phenomenon remain poorly understood. Herein, we report that lipoprotein-induced VED in a mouse model is associated with elevated inflammatory cytokines TNF-α, IL-1β, IL-6, IL-17A, and KC in lung lavage fluid and with suppurative pneumonia marked by exuberant neutrophilia in the pulmonary parenchyma. Whole-lung-digest flow cytometry and RNAScope analysis identified multiple cellular sources for IL-17A, and the numbers of IL-17A producing cells were increased in LAMPs-vaccinated/Mp-challenged animals compared to controls. Specific IL-17A or neutrophil depletion reduced disease severity in our VED model-indicating that Mp lipoproteins induce VED in an IL-17A-dependent manner and through exuberant neutrophil recruitment. IL-17A neutralization reduced levels of TNF-α, IL-1β, IL-6, and KC, indicating that IL-17A preceded other inflammatory cytokines. Surprisingly, we found that IL-17A neutralization impaired bacterial clearance, while neutrophil depletion improved it-indicating that, while IL-17A appears to confer both maladaptive and protective responses, neutrophils play an entirely maladaptive role in VED. Given that lipoproteins are found in virtually all bacteria, the potential for lipoprotein-mediated maladaptive inflammatory responses should be taken into consideration when developing vaccines against bacterial pathogens.

Pancreatic ductal adenocarcinoma (PDAC) is a highly metastatic disease. Tumors are poorly immunogenic and immunosuppressive, preventing T cell activation in the tumor microenvironment. Here, we present a microbial-based immunotherapeutic treatment for selective delivery of an immunogenic tetanus toxoid protein (TT856-1313) into PDAC tumor cells by attenuated Listeria monocytogenes. This treatment reactivated preexisting TT-specific memory T cells to kill infected tumor cells in mice. Treatment of KrasG12D,p53R172H, Pdx1-Cre (KPC) mice with Listeria-TT resulted in TT accumulation inside tumor cells, attraction of TT-specific memory CD4 T cells to the tumor microenvironment, and production of perforin and granzyme B in tumors. Low doses of gemcitabine (GEM) increased immune effects of Listeria-TT, turning immunologically cold into hot tumors in mice. In vivo depletion of T cells from Listeria-TT + GEM-treated mice demonstrated a CD4 T cell-mediated reduction in tumor burden. CD4 T cells from TT-vaccinated mice were able to kill TT-expressing Panc-02 tumor cells in vitro. In addition, peritumoral lymph node-like structures were observed in close contact with pancreatic tumors in KPC mice treated with Listeria-TT or Listeria-TT + GEM. These structures displayed CD4 and CD8 T cells producing perforin and granzyme B. Whereas CD4 T cells efficiently infiltrated the KPC tumors, CD8 T cells did not. Listeria-TT + GEM treatment of KPC mice with advanced PDAC reduced tumor burden by 80% and metastases by 87% after treatment and increased survival by 40% compared to nontreated mice. These results suggest that Listeria-delivered recall antigens could be an alternative to neoantigen-mediated cancer immunotherapy.

Immunotherapy shows promising results and revolutionizes treatment of oral squamous cell carcinoma (OSCC). The immunologic microenvironment might have prognostic/predictive implications. Morphologic immunologic parameters (inflammatory infiltrate, stromal content, and budding activity [BA] [potentially indicating epithelial–mesenchymal transition]) were evaluated in 66 human primary therapy-naive OSCCs. Intraepithelial/stromal tumor-infiltrating lymphocytes (TILs; CD3+/CD4+/CD8+/CD4+FOXP3+/IL-17A+) were quantified, and ratios were calculated. HLA class I in tumor cells was evaluated immunohistochemically. mRNA in situ hybridization to detect IFN-γ was performed. Analysis was performed within invasive front (IF) and tumor center (TCe). Decreased HLA expression was associated with low TIL density, pronounced stromal content, and high BA; IFN-γ in TILs was correlated with high-density TILs; and IFN-γ in tumor cells was correlated with absence of BA (p < 0.05). Heterogeneity of parameters (TCe/IF) was rare. Low density of stromal CD4+FOXP3+ TILs within TCe and IF was identified as an independent prognostic factor for poor overall, disease-specific, and disease-free survival (p ≤ 0.011). Refining prognostication in OSCC with high-density CD4+FOXP3+ infiltrate within TCe and/or IF, high FOXP3:CD4 ratio was significantly correlated with favorable outcome in this subgroup. Furthermore, high-stromal CD8:CD4 ratio was found to be an independent favorable prognostic factor. In summary, immunologic parameters were closely intertwined. Morphologic correlates of epithelial–mesenchymal transition were associated with downregulation of HLA and decreased inflammation. Heterogeneity was infrequent. Low-density stromal CD4+FOXP3+ infiltrate within TCe and IF was an independent poor prognostic factor. Stratification of cases with high-density CD4+FOXP3+ TILs by FOXP3:CD4 ratio enables refinement of prognostication of this subgroup. CD8:CD4 ratio was identified as an independent prognostic factor.

Chimeric antigen receptor (CAR) T cell therapy has limited efficacy against solid tumors, and one major challenge is T cell exhaustion. To address this challenge, we performed a candidate gene screen using a hypofunction CAR-T cell model and found that depletion of basic leucine zipper ATF-like transcription factor (BATF) improved the antitumor performance of CAR-T cells. In different types of CAR-T cells and mouse OT-1 cells, loss of BATF endows T cells with improved resistance to exhaustion and superior tumor eradication efficacy. Mechanistically, we found that BATF binds to and up-regulates a subset of exhaustion-related genes in human CAR-T cells. BATF regulates the expression of genes involved in development of effector and memory T cells, and knocking out BATF shifts the population toward a more central memory subset. We demonstrate that BATF is a key factor limiting CAR-T cell function and that its depletion enhances the antitumor activity of CAR-T cells against solid tumors.